Ventilating and conditioning



May 31, 1938. w. H. CARRIER ET AL VENTILATING AND CONDITIONING SYSTEM Filed April 5, 1935 2 Sheets-Sheet l INVENTORS. WILL/.5 H. CAPE/E1? m BY fo /v H. Homo/v,

AM OZ.)

ATTORNEY.

May 31, 1938. w. H. CARRIER El AL 2,119,127

VENTILATING AND CONDITIONING SYSTEM Filed April 5, 1935 2 Sheets-Sheet 2 INVENTORS. WILL/6 H. CARP/E/mvo fox-,w. H HOLT N ATTORNEY.

Patented May 31, 1938 UNITED STATES PATENT OFFICE VENTILATING AND oonnmomc srs'rsu Application April 5, 1935, Serial No. 14,812

3 Claim.

This invention relates to air conditioning, and more particularly to a method of and means for positively ventilating conditioned enclosures.

In the art of conditioning enclosures, it is general practice to recondition and recirculate air withdrawn from the enclosure, adding to the recirculated air a quantity of fresh air sufllcient to meet the physiological requirements of the occupants, to prevent the atmosphere of the enclosure from becoming vitiated and odoriferous, and to compensate for air losses through doors, windows and the like. Under certain conditions, however, systems heretofore in use have failed to add the requisite quantity of fresh air to the recirculated air, the atmosphere of the enclosure becoming unhealthy and unpleasant in consequence.

The rate of air flow established by a fan, blower or other draft device is determined in part by the static pressures existing on the intake and exhaust sides of the device. Thus, when a fan moves air from a point on the intake side of the fan to a point on the exhaust side of the fan, it will move a greater volume of air per unit time if the static pressures at both points.are the same than if the static pressure of the point on the intake side is below that of the point on the exhaust side. So also, a fan device which draws separate volumes of air from two sources of supply at thesame static pressure will continue to draw such air volumes in fixed proportion only so long as the static pressures at the sources remain unchanged; if the static pressure of one source of supply should fall, the fan would draw less air from that source, a correspondingly greater amount of air being drawn from the other source of supply. If it be assumed that a fan device supplying air to an enclosure draws air from within the enclosure and from outside the enclosure in desired proportions, it will be apparent that any fall in the outside static pressure will cause an unbalanced condition in which an insufficient quantity of outside air is supplied to the enclosure.

Such a condition of unbalance might obtain, for example, when the wind blows against a building, the fresh air intake being on the sheltered or leeward side thereof, for it is well known that an area of negative pressure is developed on the leeward side of an obstruction to the rapid flow of air. 80 also, a condition of unbalance of outdoor and indoor static pressures results from "stack effect", whenever the indoor air is warmer or colder than the outside air.

It is the general object of the invention to provide a system of and means for ventilating and conditioning an enclosure assuringa positive supply of outdoor air to the enclosure to be conditioned.

It is another object of the invention to draw 5 gases from two sources of supply in substantially constant volumetric ratio, notwithstanding variations in the static pressures of said sources of supply. a

It is another object of the invention to withdraw a volume of air from an enclosure to be conditioned, to add thereto a desired volume of -fresh air and to discharge the resultant mixture into the enclosure.

Still another object of the invention is to provide means for supplying fresh or outdoor air from a single point of supply to a plurality of conditioning units positioned in and/or serving a plurality oi enclosures.-

A further object of the invention is to provide an air conditioning and ventilating system with which desired atmospheric conditions within an enclosure may be obtained at all times, and which will be relatively simple, practical, eflicient and inexpensive.

A feature of the invention resides in the-provision of a fresh air fan in combination with a return air fan, said fans cooperating to supply to an enclosure a mixture of fresh and return air in substantially fixed proportions at all times. A feature of the invention resides in drawing air from an area of substantially constant static pressure, drawing other air from an area of variable static pressure, mixing the air drawn from each of said areas to form a mixture of substantially constant proportions, and supplying the mixture to an enclosure.

A further feature of the invention resides in the introduction of fresh air into the conditioning unit at a point beyond the return air fans, and in such a manner that substantially all of the fresh air is subjected to the conditioning action of the unit.

Still another feature of the invention resides in the provision of sound-absorbing means in combination with the fresh air fan, wher'eby quiet operation of the apparatus is assured.

Other objects and features of the invention, including advantages in design, construction and operation, will be apparent from the following description, to be read in connection with the accompanying drawings, in which:

Fig. 1 is a front elevational view, partly in section, of one form of the invention, showing the conditioning unit and the i'resh air intake unit, and the general assembly of the units within a decorative outer casing;

Fig. 2 is a section through the conditioning unit, taken on the line 2.2 of Fig. 1, showing the return air intake and the fresh air distributing duct Fig. 3 is a section through the fresh air intake unit, taken on the line 3--3 of Fig. 1, illustrating the manner in which the unit may be connected to a partially opened window;

Fig. 4 illustrates an alternative form of the invention in which a two-stage ventilating fan is utilized.

Referring now to the drawings, and considering particularly Figs. 1-3, te numeral .lll designates generally a casing housing the conditioning unit Ii and the fresh air intake unit I2. Fans ll of the unit II are suitably driven, as by motor ll, and draw air from the enclosure through the grille l5 of the casing Ill and through a filter I5 of any desired type, discharging it upwardly through the unit. When humidification is required, water is fed to nozzle I! through supply pipe l8 and is impinged against target I9, whereby it is distributed throughout the unit as fine spray, readily to be taken up by air passing through the unit. Plates 45 serve to distribute the recirculated air throughout the unit and to prevent the drainage of excess spray water into the fan scrolls. Such water collects in the channels 46 of plates 45 and is delivered to sump 23.

Partition 28, extending throughout the length of the unit ll, divides the upper part of the unit into two passageways. In one of these are positioned the conditioning coils 2| of the finned or other desired type, which may be supplied with refrigerant during the warmer periods of the year, or with steam, hot water or the like for heating during the colder periods of the year. If desired, of course, separate heating coils and cooling coils may be provided. In the other passageway are positioned the eliminator plates 22, the function of which is to remove entrained spray water from air passing therethrough. Such water, or water condensed from the air by coils 2| when cooling and dehumidification are effected, falls into sump 23, whence it may be disposed of in any desired manner, as by drainage through outlet 24. Dampers control the proportions of air passing through the conditioning coils and through the bypass.

Fresh air is supplied to the unit |2 through the duct 25. The outdoor opening of this duct may be positioned in accordance with engineering expedience. For purposes of illustration, the duct is shown connected to a partially opened window 21 in the wall 28 of the enclosure. The fresh air is drawn in through duct 28 and through filter 28, as by the fan 38, driven by motor 3|. 1

The function of the fan 3|! is to provide a positive supply of fresh air to the enclosure, notwithstanding such difierence in static pressure as may exist between the enclosure and the outdoors. Accordingly, fan 30 is designed 'to run at comparatively high speeds, in order that it may overcome a relatively low outdoor static pressure. High speed fans are noisy in operation, however. Thus, applicant provides a sound absorbing system in the .base of unit |2 to deaden the sound of the fans. The sound absorber consists of a series of fibre ballies 32, in-the sealed casing of the unit l2, which provide a tortuous path for the air. Deflector plates 33 distribute the air discharged by the fan 30 throughout the width of the unit l2. The air then passes through the sound-absorbing baiiie arrangement to the rear of unit I2, and is discharged into connecting duct 34.

From duct 34, the fresh air passes into distributing duct 35 in unit ll. As illustrated, this distributing duct has a discharge opening 35 extending substantially throughout the length of unit II. It is to-be noted that the fresh air is introduced into unit above the recirculated air fans l8. These fans, then, are not required to handle b. return and fresh air, as in the conventional unit, but return air only. Thus, the total volume of air passing through the unit II to the enclosure is not that handled by the fans 3 alone, but that handled by the fans l3 and the fan 30, so that the total air capacity of the unit II is increased.

Generally, the return air is more nearly suitable for distribution to the enclosure, and re quires less conditioning, than the fresh air. It is generally desirable, therefore, that practically all of the fresh air be conditioned, whereas part of the return air may be bypassed around the heat exchanger coils. Accordingly, in the preferred arrangement illustrated, the opening 38 is located under coils 2| so that substantially all of the air flowing through the opening is directed in contact with the coils 2 I except in the extreme case when the dampers 25 are closed. In this arrangement, substantially all of the air flowing through the bypass is return air.

Dampers 25 are pivotally mounted and adapted to swing from a horizontal position to a position approaching vertical. When the dampers 25 are in a horizontal position, they cover the heat exchange coils 2|, and prevent air from passing through the passageway in which the-coils are situated. When the dampers 25 are in this horizontal position, substantially all of the air passing through the unit (both fresh and return air) passes through the chamber in which plates 22 are situated. When the dampers 25 are swung upwardly, they permit the passage of air through the passageway having coils 2|. When the right hand damper 25, (as seen in Fig. 2) is raised to its maximum position, it permits maximum air flow through coils 2| and cuts off air flow through plates 22. Intermediate positions of the right hand damper 25 cause desired portions of the total air handled by the unit to pass in contact through the coils 2|, and through the plates 22. Ordinarily, the dampers 25 are so adjusted that air flows through both the coils 2| and the plates 22. Because the fresh air duct 35 opens directly under the coils 2|, substantially all of the air issuing from duct 35 passes upwardly through the coils 2|, while the room air discharged by the fan |3, passes partly through the plates 22 and partly through the coils 2|.

Should the outdoor static pressure approximate or become greater than that of the enclosure, or should the wall 28 be on the windward rather than on the leeward side of the enclosure, fan 3|) would tend to supply an excessive quantity of fresh air to the enclosure. As provision against such oversupply, applicant places in duct 26 a self-regulating draft check 31, comprising a vane portion 38 and a counterweight portion 39.

As air passes into duct 26 at an excessive rate,

the pressure on the vane 38 tends to swing the vane shut, thus restricting the passageway and reducing the flow of air through the duct. When the pressure is relieved, counterweight 39 swings the vane open.

It will be seen, therefore, that applicant provides for the supply of a substantially fixed amount of fresh air to the unit H, regardless of the static pressure or wind conditions outdoors. The fresh air is mixed in the unit II with the return air in predetermined proportions, and the mixture, suitably conditioned, is discharged into the enclosure through the grille 40. A damper may be provided in the fresh air intake for varying the fresh air supply.

As illustrated and described, the ventilating and conditioning units are housed in the same casing. It will be understood, however, that the outer casing I is merely decorative and, if desired, may be dispensed with. Further, the

two units need not be adjacent each other, but,

if desired, may be positioned in diil'erent parts of the enclosureor building served. Again, the unit I2 may be designed to serve a plurality of conditioning units H. in dot and dash lines inFig. 1, may convey fresh air to another conditioning unit remote from the unit l2 illustrated, or to a series of remote conditioning units.

In the alternative form of the invention illustrated in Fig. 4, the high speed fan 30 is replaced by a two-stage fan 4| comprising sections la and lib. The static pressure built up by a fan is a function of the speed of the fan. Static pressure, however, may be built up in steps. Therefore, the two fan sections Ma and lib, in staged or successive operation, while running at a speed considerably less than that of the fan 3|), can draw in as much air against a reduced outdoor static pressure as the single stage high speed fan 30. The fan 4| may be designed to operate at the same speed as the fan I3, handling recirculated air. In' such case, motor [4 may serve to drive both the fresh air and recirculated air fans, and motor 3| may be dispensed with. Further, when fan sections Ila and llb operate at reduced speed, they produce only a slight amount of noise, negligible in most applications. Thus, the sound absorber arrangement of Figs. 1 and 3 may also be eliminated.

Since certain changes in carrying out. the

Thus, duct a, shown,

above method of operation and in the construc: tions set forth, which embody the invention, may be made without departing from its scope. it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. In an air conditioning apparatus, a first passage, conditioning means in said first passage, 3. second passage adjacent said first passage, means including a duct below said first passage and running substantially lengthwise thereof for routing a first volume of fresh air through said first passage only, in contact with said conditioning means, and means for supplying a second volume of return air to said second passage, and means for supplying said first and second air volumes to an enclosure served by the apparatus.

2. In an air conditioning unit, a casing, means within the casing for forming within the casing a first passageway and a second passageway, heat exchange means in said first passageway, means for drawing air from a first source and for routing said air through said first passageway exclusively, means for drawing air from another source and routing said last mentioned air through said first and second passageways, and means for supplying to the enclosure served by the unit air from said first and second passageways.

3. In an air conditioning apparatus, a first passage, conditioning means in said first passage, a second passage adjacent said first passage, means including a duct below said first passage and running substantially lengthwise thereof for routing a first volume of fresh air through said first passage only, in contact with said conditioning means, means for supplying a second volume of return air to said second passage and said first passage, and means for supplying said first and second air volumes to an enclosure served by the apparatus.

WILLIS H. CARRIER. JOHN H. HOLTON.

DISCLAIMER 2,119,I 27.-Willis H. Carrier, Essex Fells, and John H. Holton, Maplewood, N. J. VENTILATING AND CONDITIONING SYSTEM. Patent dated May 31, 1938.

Disclaimer filed September 30, 1939, by the assignee, Carrier Corporation. Hereby enters this disclaimer to claim 2 of said specification, except as relating to a unit comprising two adjacent horizontally extending passageways through each of which air is caused to flow in a vertical direction, the air circulated through said first passageway by-Eassingsaid second passageway, and the air passing through sa1d second passageway y-passing said first passageway, onl

one of said passageways containmg heat exchange means for thermal treatment 0 air circulated through said unit.

[Oflic'ial Gazette October 24, 1939.]

It will be seen, therefore, that applicant provides for the supply of a substantially fixed amount of fresh air to the unit H, regardless of the static pressure or wind conditions outdoors. The fresh air is mixed in the unit II with the return air in predetermined proportions, and the mixture, suitably conditioned, is discharged into the enclosure through the grille 40. A damper may be provided in the fresh air intake for varying the fresh air supply.

As illustrated and described, the ventilating and conditioning units are housed in the same casing. It will be understood, however, that the outer casing I is merely decorative and, if desired, may be dispensed with. Further, the

two units need not be adjacent each other, but,

if desired, may be positioned in diil'erent parts of the enclosureor building served. Again, the unit I2 may be designed to serve a plurality of conditioning units H. in dot and dash lines inFig. 1, may convey fresh air to another conditioning unit remote from the unit l2 illustrated, or to a series of remote conditioning units.

In the alternative form of the invention illustrated in Fig. 4, the high speed fan 30 is replaced by a two-stage fan 4| comprising sections la and lib. The static pressure built up by a fan is a function of the speed of the fan. Static pressure, however, may be built up in steps. Therefore, the two fan sections Ma and lib, in staged or successive operation, while running at a speed considerably less than that of the fan 3|), can draw in as much air against a reduced outdoor static pressure as the single stage high speed fan 30. The fan 4| may be designed to operate at the same speed as the fan I3, handling recirculated air. In' such case, motor [4 may serve to drive both the fresh air and recirculated air fans, and motor 3| may be dispensed with. Further, when fan sections Ila and llb operate at reduced speed, they produce only a slight amount of noise, negligible in most applications. Thus, the sound absorber arrangement of Figs. 1 and 3 may also be eliminated.

Since certain changes in carrying out. the

Thus, duct a, shown,

above method of operation and in the construc: tions set forth, which embody the invention, may be made without departing from its scope. it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. In an air conditioning apparatus, a first passage, conditioning means in said first passage, 3. second passage adjacent said first passage, means including a duct below said first passage and running substantially lengthwise thereof for routing a first volume of fresh air through said first passage only, in contact with said conditioning means, and means for supplying a second volume of return air to said second passage, and means for supplying said first and second air volumes to an enclosure served by the apparatus.

2. In an air conditioning unit, a casing, means within the casing for forming within the casing a first passageway and a second passageway, heat exchange means in said first passageway, means for drawing air from a first source and for routing said air through said first passageway exclusively, means for drawing air from another source and routing said last mentioned air through said first and second passageways, and means for supplying to the enclosure served by the unit air from said first and second passageways.

3. In an air conditioning apparatus, a first passage, conditioning means in said first passage, a second passage adjacent said first passage, means including a duct below said first passage and running substantially lengthwise thereof for routing a first volume of fresh air through said first passage only, in contact with said conditioning means, means for supplying a second volume of return air to said second passage and said first passage, and means for supplying said first and second air volumes to an enclosure served by the apparatus.

WILLIS H. CARRIER. JOHN H. HOLTON.

DISCLAIMER 2,119,I 27.-Willis H. Carrier, Essex Fells, and John H. Holton, Maplewood, N. J. VENTILATING AND CONDITIONING SYSTEM. Patent dated May 31, 1938.

Disclaimer filed September 30, 1939, by the assignee, Carrier Corporation. Hereby enters this disclaimer to claim 2 of said specification, except as relating to a unit comprising two adjacent horizontally extending passageways through each of which air is caused to flow in a vertical direction, the air circulated through said first passageway by-Eassingsaid second passageway, and the air passing through sa1d second passageway y-passing said first passageway, onl

one of said passageways containmg heat exchange means for thermal treatment 0 air circulated through said unit.

[Oflic'ial Gazette October 24, 1939.] 

